<?php

class Encryption {

    const
            CYPHER = MCRYPT_RIJNDAEL_128,
            MODE = 'cbc',
            SALT = '';

    /**
     * Encrypt string using mcrypt module
     * @param string $plaintext Text to be encrypted
     * @param string $password User entered password
     */
    public static function encrypt($plaintext, $password = '') {
//        $td = mcrypt_module_open(self::CYPHER, '', self::MODE, '');
//        $iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
//        $key = self::SALT . trim($password);
//        mcrypt_generic_init($td, $key, $iv);
//        $crypttext = mcrypt_generic($td, $plaintext);
//        mcrypt_generic_deinit($td);
//        $crypttext = $iv . $crypttext;
//        return $crypttext;
       return mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $password, self::pkcs5_pad($plaintext), MCRYPT_MODE_ECB);
    }

    /**
     * Decrypt string using mcrypt module
     * @param string $crypttext Text to be decrypted
     * @param string $password User entered password
     */
    public static function decrypt($crypttext, $password = '') {
        $td = mcrypt_module_open(self::CYPHER, '', self::MODE, '');
        $ivsize = mcrypt_enc_get_iv_size($td);
        $iv = substr($crypttext, 0, $ivsize);
        $crypttext = substr($crypttext, $ivsize);
        $key = self::SALT . trim($password);
        mcrypt_generic_init($td, $key, $iv);
        return mdecrypt_generic($td, $crypttext);
    }

    public static function pkcs5_pad($text, $blocksize = 16) {
        $pad = $blocksize - (strlen($text) % $blocksize);
        return $text . str_repeat(chr($pad), $pad);
    }

    public static function pkcs5_unpad($text) {
        $pad = ord($text{strlen($text) - 1});
        if ($pad > strlen($text))
            return false;
        if (strspn($text, chr($pad), strlen($text) - $pad) != $pad)
            return false;
        return substr($text, 0, -1 * $pad);
    }


}